Electronic fuel control devices that provide an electrical signal in response to the drivers demand for engine power are known in the art. Known devices comprise generally a potentiometer that is linked to a foot pedal by mechanical linkage to provide an electrical signal proportional to the rotational position of the potentiometer. Prior art devices in general have the potentiometer remotely located from the foot pedal, and connecting linkages such as rods, bell cranks, cables etc., are employed to link the pedal to the potentiometer. These linkages are a potential source of poor transmission of pedal position and are prone to have performance degradation due to wear, contamination, bending, and binding. In addition, the linkage requires a great deal of maintenance and introduces friction and wear in the linkage joints producing looseness and back-lash resulting in degradation of the signal generated.
In most prior art devices the potentiometer is placed in the engine compartment which exposes the potentiometer to a hostile enviroment where heat, vibration, and grime hasten the deterioration of the control system.
Idealy, a 20 degree rotation of the foot pedal is optimum for driver comfort and degree of control. A potentiometer using only 20 degrees rotation from minimum signal to maximum signal has less signal resolution over the extent of the potentiometers travel. Preferably, 40 to 60 degrees of potentiometer shaft rotation produces a high quality of voltage signal. The ideal foot pedal control eliminates all lost motion between pedal movement and potentiometer movement. In addition the ideal electronic foot pedal control will place no side load or thrust load on the potentiometer shaft which would induce wear and early failure.
The present invention overcomes the above problems by providing an integrated package with a foot pedal and potentiometer which can be conveniently located in the cab of the vehicle. The present invention provides a three to one multiplication of pedal rotation to potentiometer shaft rotation. In addition the present invention provides an interference fit between the rotating shaft of the foot pedal device and the potentiometer shaft eliminating all lost motion.